Touchscreens are widely used as displays for electronic devices. A touchscreen enables a user to interact with that which is displayed directly, instead of indirectly by a mouse, touch pad or other input device. Touchscreens are used, for example, in mobile communication devices.
There are at least two main categories of touchscreens, such being resistive touchscreens and capacitive touchscreens. A resistive touchscreen includes several layers, two of which are electrically conductive layers separated by a narrow gap. When an object, such as a finger or stylus presses on the resistive touchscreen, the gap is closed so that a connection between those two electrically conductive layers is made. The contact between the two layers causes a change in the current which is registered as a touch event for processing.
A capacitive touchscreen includes an insulator layer such as glass that is coated with a transparent conductor such as indium tin oxide (ITO). Bringing a finger or conductive stylus within close proximity of the capacitive sensor changes the local electrostatic field. A user is grounded, therefore, the circuit of the touchscreen and the finger or conductive stylus is completed. The location of the one touch or multiple touches can be measured by a grid. A fine grid can provide high resolution of the capacitive touchscreen which makes a capacitive touchscreen a preferred touchscreen for smaller electronic devices.